Editing Ostracod (section)

==Ecology==

===Lifecycle===
Male ostracods have two [[penis]]es, corresponding to two genital openings ([[gonopore]]s) on the female. The individual sperm are often large, and are coiled up within the [[testis]] prior to mating; in some cases, the uncoiled sperm can be up to six times the length of the male ostracod itself. Mating typically occurs during swarming, with large numbers of females swimming to join the males. Some species are partially or wholly [[Parthenogenesis|parthenogenetic]].<ref name=IZ/> Superfamily Darwinuloidea was assumed to have reproduced asexually  for the last 200 million years, but rare males have since been discovered in one of the species.<ref>{{cite journal |last1=Smith |first1=Robin J |last2=Kamiya |first2=Takahiro |last3=Horne |first3=David J |title=Living males of the 'ancient asexual' Darwinulidae (Ostracoda: Crustacea) |journal=Proceedings of the Royal Society B: Biological Sciences |date=22 June 2006 |volume=273 |issue=1593 |pages=1569–1578 |doi=10.1098/rspb.2005.3452 |pmid=16777754 |pmc=1560310 }}</ref>
[[File:Karpvähiline.jpg|thumb|Ostracod]]
In the subclass Myodocopa, all members of the order Myodocopida have brood care, releasing their offspring as first instars, allowing a pelagic lifestyle. In the order Halocyprida the eggs are released directly into the sea, except for a single genus with brood care. In the subclass Podocopa, brood care is only found in Darwinulocopina and some Cytherocopina in the order Podocopida. In the remaining Podocopa it is common to glue the eggs to a firm surface, like vegetation or the substratum. These eggs are often resting eggs, and remain dormant during desiccation and extreme temperatures, only hatching when exposed to more favorable conditions.<ref>[https://books.google.com/books?id=XYOPpkBuuTIC&dq=%22avoid+brooding+and+simply+glue+the+eggs+to+a+firm+surface+and+then+abandon+them%22&pg=PA141 Field Guide to Freshwater Invertebrates of North America]</ref><ref>[https://books.google.com/books?id=orzLHglZlEUC&dq=%22In+the+subclass+Myodocopa%2C+all+representatives+of+Myodocopida+have+brood+care%22&pg=PA59 Recent Freshwater Ostracods of the World: Crustacea, Ostracoda, Podocopida]</ref> Species adapted to [[vernal pool]]s can reach sexual maturity in just 30 days after hatching.<ref>[https://www.theguardian.com/environment/2019/mar/26/specieswatch-ancient-crustaceans-still-going-strong-after-450m-years Specieswatch: ancient crustaceans still going strong after 450m years]</ref> There is no larval stage or metamorphosis ([[direct development]]). Instead they hatch from the egg as juveniles with the bivalved carapace and at least three functional limbs. As the juvenile grows through a series of molts they acquire more limbs and develop further the already existing ones.<ref>[https://marinescience.ucdavis.edu/sites/g/files/dgvnsk9221/files/inline-files/BMR_Ostracoda.pdf The Light and Smith Manual : Intertidal Invertebrates from Central California to Oregon – Page 419]</ref> They reach sexual maturity in the final instar and then never molts again. The number of instars they go through before adulthood varies. In Podocopa it is eight or nine (but family Entocytheridae and suborder Bairdiocopina has only seven),<ref>[https://books.google.com/books?id=orzLHglZlEUC&dq=Entocytheridae+Bairdiocopina+seven+instars&pg=PA62 Recent Freshwater Ostracods of the World: Crustacea, Ostracoda, Podocopida]</ref> the Halocyprida goes through six or seven, and Myodocopida only four to six. They are able to produce several offspring many times as adults ([[Semelparity and iteroparity#Iteroparity|iteroparity]]).<ref>[https://media.australian.museum/media/Uploads/Journals/17619/378_complete.pdf Strategies of crustacean growth - Australian Museum]</ref><ref>[https://books.google.com/books?id=1FQPEAAAQBAJ&dq=%22Ostracods+become+mature+only+in+the+final+instar%22&pg=PT131 Crustacean Issues 3: Factors in Adult Growth]</ref><ref>[https://books.google.com/books?id=Z2tEEAAAQBAJ&dq=Podocopa+eight+nine+stages+Myodocopa+Halocyprida+six+seven+Myodocopida+four&pg=PA130 Evolution and Phylogeny of Pancrustacea: A Story of Scientific Method]</ref>

===Predators===
A variety of fauna prey upon ostracods in both aquatic and terrestrial environments. An example of predation in the marine environment is the action of certain Cytherocopina in the [[Cuspidariidae|cuspidariid clams]] in detecting ostracods with [[cilia]] protruding from inhalant structures, thence drawing the ostracod prey in by a violent suction action.<ref>{{cite book |author1=John D. Gage  |author2=Paul A. Tyler  |name-list-style=amp |title=Deep-Sea Biology: A Natural History of Organisms at the Deep-Sea Floor |publisher=[[University of Southampton]] |isbn=978-0-521-33665-9|date=1992-09-28  }}</ref> Predation from higher animals also occurs; for example, amphibians such as the [[rough-skinned newt]] prey upon certain ostracods.<ref>{{cite web |author=C. Michael Hogan |year=2008 |title=''Rough-skinned Newt ("Taricha granulosa")'' |website=[[Globaltwitcher]], ed. N. Stromberg |url=http://www.globaltwitcher.com/artspec_information.asp?thingid=43182 |url-status=dead |archive-url=https://web.archive.org/web/20090527153302/http://www.globaltwitcher.com/artspec_information.asp?thingid=43182 |archive-date=2009-05-27 }}</ref> Whale sharks also seem to eat them as part of their filter feeding process.<ref>{{cite journal |last1=Rohner |first1=Ca |last2=Couturier |first2=Lie |last3=Richardson |first3=Aj |last4=Pierce |first4=Sj |last5=Prebble |first5=Cem |last6=Gibbons |first6=Mj |last7=Nichols |first7=Pd |title=Diet of whale sharks Rhincodon typus inferred from stomach content and signature fatty acid analyses |journal=Marine Ecology Progress Series |date=20 November 2013 |volume=493 |pages=219–235 |doi=10.3354/meps10500 |bibcode=2013MEPS..493..219R }}</ref>



===Bioluminescence===
Some ostracods, such as ''[[Vargula hilgendorfii]]'', have a light organ in which they produce luminescent chemicals.<ref>{{Cite book |title=Bioluminescence: Chemical Principles and Methods |chapter=The ostracod ''Cypridina'' (''Vargula'') and other luminous crustaceans |author=Osamu Shimomura |chapter-url=https://books.google.com/books?id=DNrTfH5PcWoC&pg=PA49 |isbn=978-981-256-801-4 |publisher=[[World Scientific]] |year=2006 |pages=47–89}}</ref> These ostracods are called "blue sand" or "blue tears" and glow blue in the dark. Their [[bioluminescent]] properties made them valuable to the Japanese during [[World War II]], when the Japanese army collected large amounts from the ocean to use as a convenient light for reading maps and other papers at night. The light from these ostracods, called ''umihotaru'' in Japanese, was sufficient to read by but not bright enough to give away troops' position to enemies.<ref name="jabr">{{cite web|last1=Jabr|first1=Ferris|title=The Secret History of Bioluminescence|url=https://www.hakaimagazine.com/article-long/secret-history-bioluminescence|website=Hakai Magazine|access-date=6 July 2016}}</ref> Bioluminescence has evolved twice in ostracods; once in [[Cypridinidae]], and once in [[Halocyprididae]].<ref>{{cite journal |last1=Cohen |first1=Anne C. |last2=Oakley |first2=Todd H. |title=Collecting and processing marine ostracods |journal=Journal of Crustacean Biology |date=May 2017 |volume=37 |issue=3 |pages=347–352 |doi=10.1093/jcbiol/rux027 }}</ref> In bioluminescent Halocyprididae a green light is produced within carapace glands, and in Cypridinidae a blue light is produced and extruded from the upper lip.<ref>{{cite journal |last1=Cohen |first1=Anne C. |last2=Morin |first2=James G. |title=Sexual Morphology, Reproduction and the Evolution of Bioluminescence in Ostracoda |journal=The Paleontological Society Papers |date=November 2003 |volume=9 |pages=37–70 |doi=10.1017/S108933260000214X }}</ref><ref>{{cite journal |last1=Morin |first1=James G. |last2=Cohen |first2=Anne C. |title=Two New Bioluminescent Ostracode Genera, Enewton And Photeros (Myodocopida: Cypridinidae), with Three New Species from Jamaica |journal=Journal of Crustacean Biology |date=2010 |volume=30 |issue=1 |pages=1–55 |doi=10.1651/08-3075.1 |bibcode=2010JCBio..30....1M }}</ref> Most species use the light as predation defense, but the male of at least 75 known species of the Cypridinidae, restricted to the Caribbean, use pulses of light to attract females. Some species are the opposite where the females use pulses of light to attract males. This is seen in one example such as the [[Lampyris noctiluca|glow worm]]. This bioluminiscent [[courtship display]] has only evolved once in ostracods, in a cypridinid group named Luxorina that originated at least 151 million years ago.<ref>{{cite journal |last1=Ellis |first1=Emily A |last2=Goodheart |first2=Jessica A |last3=Hensley |first3=Nicholai M |last4=González |first4=Vanessa L |last5=Reda |first5=Nicholas J |last6=Rivers |first6=Trevor J |last7=Morin |first7=James G |last8=Torres |first8=Elizabeth |last9=Gerrish |first9=Gretchen A |last10=Oakley |first10=Todd H |title=Sexual Signals Persist over Deep Time: Ancient Co-option of Bioluminescence for Courtship Displays in Cypridinid Ostracods |journal=Systematic Biology |date=16 June 2023 |volume=72 |issue=2 |pages=264–274 |doi=10.1093/sysbio/syac057 |pmid=35984328 |pmc=10448971 }}</ref><ref>{{cite journal |last1=Rivers |first1=Trevor J. |last2=Morin |first2=James G. |title=Female ostracods respond to and intercept artificial conspecific male luminescent courtship displays |journal=Behavioral Ecology |date=2013 |volume=24 |issue=4 |pages=877–887 |doi=10.1093/beheco/art022 }}</ref> Ostracods with bioluminescent courtship show higher rates of [[speciation]] than those who simply use light as protection against predators.<ref>[https://nautil.us/bioluminescence-is-natures-love-light-243320/ Bioluminescence Is Nature's Love Light]</ref> The male will continue to swim after releasing its small ball of bioluminescent mucus, but the female is able to read the display to pinpoint the male's location.<ref>[https://www.nytimes.com/2023/11/28/science/sea-fireflies-glowing.html Watch ‘Sea Fireflies’ Make Underwater Fireworks as They Seek Mates]</ref> In one species hundreds of thousands of males synchronize their light display, and when one male creates a pattern of light, the new pattern will spread out as the neighboring males repeat it.<ref>[https://www.cbc.ca/radio/asithappens/sea-firefly-mating-dance-1.7046972 Mating dance of sea fireflies is 'the coolest fireworks show that you've ever seen']</ref>